Advances in sequencing and deciphering of genomes have given rise to a field of research that may just be two orders of magnitude more complex, the human microbiome. Continued innovation in genomic sequencing combined with advances in areas such as metabolomics are leading to a more complete understanding of the human microbiome.
- Different bodily environments harbor differing concentration and diversity of microbial species, with research investment varying between these niche habitats.
- Currently, it is unclear which species may be good targets for intervention, but dysbiosis is thought to play a role in a diverse set of diseases.
- Several diseases covered by DRG research and reports are the focus of ongoing research in this area, including COPD and IBD (i.e., Ulcerative Colitis and Crohn’s disease), where connections between microbiota dysregulation to the underlying pathogenesis of the disease have been an intense focus of investigation.
It may come as a surprise, but only about 1% of genes in your body are actually yours. The majority of what constitutes your genetic makeup is provided by the prodigious (think TRILLIONs) and diverse organisms living among you. The collective functionality and underlying ecosystem the genomes of these organisms create gives microbiome its name. Understanding of the human microbiome is in its infancy; however, the impact that understanding this microscopic community may have on health and well-being has gained significant attention. So, what exactly is the microbiome, and what is the current state of knowledge about how it impacts disease? How do current disease treatments impact this ecosystem, and what interventions are possible? These questions will be answered in a two-part blog series.
Humans play host to a robust community of microbiota; the majority of the time these exist in a symbiotic relationship with their host. The majority of these are bacteria, although fungi play a role in some environments, and the majority of species are either commensalistic, offering neither benefit nor harm to us, or are symbiotic, offering some advantage. There are four primary environments where distinct microbial communities are found, and their diversity and associated importance to health roughly correlates with the amount of funding each receives from the U.S. government. First, the gut (when including the entire digestive tract such as the rectum) has the highest concentration as well as diversity of bacterial species, with over 1,000 different types including strains of Bacteroides, Fermicutes, and Prevotella whose presence and interactions with other elements of the gut have been associated with inflammatory conditions. While microbiome R&D funding overall (including agricultural, aquatic, and human environments, among others) has seen a healthy rise in recent years, with nearly 1 billion in total funding over the three-year period of 2012-2014 from federal programs within the U.S., funding dedicated for the human microbiome made up over 37%, with GI-related microbiome research receiving the bulk (55%) of that funding, worth $188M. Second, the urogenital tract has its own distinct microbiome, and received 13% of funds. Third, the respiratory system including the nose, mouth, lungs and bronchial tubes are replete with bacteria, including Prevotella, Veillonella, and Actinomyces, with 11% of funding, at $37.6 M. Fourth, the skin harbors a large number of microbial species, with different populations on various parts of the body, and 3% of funding dollars.
Current understanding is that a healthy microbiotic community plays a key role in keeping potentially pathogenic species (E. coli, P. aeruginosa, or S. aureus, for example) in check. Dysbiosis, or when the microbiotic community falls out of balance is thought to contribute a great deal to many inflammatory disorders and other conditions although the exact resulting structure of these communities is not always well-defined. Conditions that trigger dysbiosis can include genetic factors, lifestyle (e.g., diet, smoking) or even environmental cues; community-acquired infections are among the most dangerous triggers for dysbiosis, especially in the hospital setting.
Continuing to build on the wealth of information provided by the Human Genome Project, researchers are currently attempting to define what constitutes a “healthy” microbiome through data from the Human Microbiome Project. Along with an increasing amount of academic research effort, there have already been some major investments into commercial ventures exploring a variety of potential interventions ranging across all the environments discussed here and beyond. While these translational interventions are likely many years away, the scope and focus of these investments will be discussed in an upcoming post.